Consequently, the former favourite of the Camp Nou suspects that Los Blancos will struggle to get past the Catalans in the quarter-finals of the Copa del Rey.
"Madrid can win one game against Barca, but two games is more difficult," Stoichkov said during an interview with Esports COPE.
However, Stoichkov, speaking ahead of the first-leg clash between the two great rivals at Santiago Bernabeu on Wednesday night, acknowledged that the one thing that Madrid do have in their favour is the tactical genius of coach Jose Mourinho.
Indeed, Stoichkov believes that the Portuguese is "one of the greatest coaches in the world" and resisted the invitation during the interview to admonish Mourinho over his apparent fondness for causing controversy.
"I have never spoken ill of a friend," the former Bulgaria international declared. "He was my coach [at Barcelona] and I have great respect for him."
However, Stoichkov did suggest that Madrid could learn something from the way in which Barca try to conduct themselves on and off the field.
"Barca is a club of gentleman," he claimed. "They have just forgotten many things to complain about in order to play good football and that's the big difference with Madrid.
"Protesting does not achieve anything and that's how the club [Barca] proves itself to be the best in the world."
During two separate spells with Barcelona, the second of which coincided with Mourinho's time at Camp Nou as a young assistant coach, Stoichkov scored 83 goals in 177 games for the club.
Starting in November and continuing through January, Goal.com is publishing exclusive extracts from Graham Hunter's highly-anticipated new book, 'Barca: The Making of the Greatest Team in the World'. The latest extract takes a closer look at the exciting emergence of Fifa Ballon d'Or winner Lionel Messi at Camp Nou: Don't miss it!